How can I get dog wee stains off outdoor tiles?

[MeeWhoo]

Any ideas will be much appreciated.

How long have they been there? I hose the yard down every day if it doesn't rain, and once a week sprinkle some dettol type disinfectant and then hose that off.

If you have set in stains then I would use Jeyes fluid and scrub it with a stiff outdoor broom

They are from the past few days (my parents have got a new puppy) but they don't come out with scrubbing . Will try the Jeyes fluid, thanks a lot.